Thursday was a red letter day for exoplanet astronomers -- it was the day that marked the announcement of the discovery of Kepler-452b, an alien world that possesses more Earth-like traits than any exoplanet discovered before it.

Although our solar system doesn't contain gas giants with thick atmospheres enriched with helium, observations by NASA's Spitzer Space Telescope suggests the galaxy may be strewn with these planetary oddities.

Earth is in what's called the habitable zone. It's far enough from the sun that it doesn't get fried, and close enough that it gets the best of its warmth. We like to think we're special for this, but it turns out we might be pretty run of the mill.